1. Field of Invention
The present invention relates to an insertion device in which a movement portion moved by receiving a movement driving force is provided in an inserting section extending along a longitudinal axis or an attachment unit which is attached to the inserting section.
2. Description of Related Art
US 2012/0029281 discloses an endoscope device which is an insertion device, an attachment unit is attached to an inserting section extending along a longitudinal axis. The attachment unit includes a base tube to which the inserting section is inserted, and a fin which is spirally extended on an outer peripheral surface of the base tube. The attachment unit including the fin which is a movement portion rotates in one of directions around the longitudinal axis with respect to the inserting section when a movement driving force is transmitted. When the attachment unit including the fin rotates in a state that the fin is abutted to a lumen wall (lumen paries), etc., a propulsive force toward a distal direction or a propulsive force toward a proximal direction acts on the inserting section. In other words, when the fin motions in a state that a pressing force acts toward the inner peripheral direction, a propulsive force acts on the inserting section in one of the axis-parallel directions parallel to a longitudinal axis.
In this endoscope, an operation section is provided to the proximal side with respect to the inserting section. The operation section includes a grip held by an operator, and a member inserting section which opens to the outside. An electronic motor, which is a driving source for generating a movement driving force to rotate the fin (movement section), is attached to the member inserting section. In the inside of the inserting section, a driving shaft which is a line portion is extended along the longitudinal axis. Upon transmission of a movement driving force from the electric motor to the driving shaft, the driving shaft rotates about a line core axis. Upon rotation of the driving shaft, the movement driving force is transmitted to the fin via a base tube of the attachment unit, and the attachment unit rotates toward one of the directions around the longitudinal axis. The line core axis of the driving shaft is bent inside the operation section toward the member inserting section. Accordingly, between the bent position and the member inserting section, the line core axis is not parallel to the longitudinal axis.